Why are there air bubbles in my drywall mud after adding water to thin it out for skin coating, despite it going on smooth initially?
Asked by Abhishek Adiga 
2 months ago
Last Updated: October 21, 2024
What makes drywall mud get those pesky air bubbles? I was doing some wall smoothing and everything seemed fine at first, but then those little bubbles started popping up all over the place about five minutes in.
Could it be that I added a touch too much water to make it thinner? I’ve seen lots of folks add water and stir without any bubble troubles.
Maybe you mixed it too much? I believe that can introduce air into it if you overdo it. Get opinions from others. Only add water if you are confident in what you’re doing, I’d say. However, many people do add water … I personally have not done it extensively (just very small quantities).
Was this the initial coat? It’s possible that you applied it too generously. High humidity could also be a factor.
Agreed, start with the initial coat on the taped seams.
Bell it seems like you might have put it on a bit too thick
https://www..com/reel/2499981960148742?fs=e&s=TIeQ9V&mibextid=jaSYs6
What surface are you covering? If it’s old paint or primer, that’s probably the reason!
Joe ohue eggsactly
Add a bit of Dawn to the bucket before mixing the skim coat.
I think I’ll give that a try
Bell likes to wear glasses while sanding 😄😄😄
I usually pour in around 10-12 ounces of water into a 5-gallon bucket.
I poured in about half of a water bottle, maybe around 10oz?
Bell is not a problem.
Bell might need to apply more on the second coat. It really depends on personal preference. I personally prefer using green top mud. It could vary for black or blue top pre mix
If your skim coat is not spreading smoothly, consider adding more pressure with your drywall knife.
Maybe your knife needs a little more pressure or a bit more mixing. It’s not a big deal if it’s not perfect on the first try.
What tool do you use for skim coating? I personally use a long squeegee and it works really well. I’ve never had problems with bubbles and sanding has been minimal.
No matter what anyone tells you, never mix dish soap with drywall mud. Instead, consider using no-pock and a small amount of water. The bubbles often form due to excessive mixing or introducing air into the mud, or using hot mud on a porous surface. I have experience in drywall work and I frequently observe this issue with new workers.
Also recommends the dish soap hack!
Advises against using dish soap.
Mentions that he is not using hot mud, but acknowledges the possibility of over-mixing.
Bell recommends taking it slow and steady when using a big egg beater to avoid whipping instead of mixing, which leads to bubbles. He suggests mixing at a low speed before hanging rock to prevent bubbles in the mud.
I appreciate the suggestions. I’ll attempt to work more slowly to see if it makes a difference. While I have experience with drywall work, thinning it down for a skin coat is a new challenge for me.
You probably applied too much of it at once.
Apply, remove.
The air bubbles may show up in the initial layer, but subsequent coats will hide them.
Dust or a thin layer of paint on top, not necessarily a problem with the consistency or length of time it was mixed.
Using dish soap and mixing at a low speed. Honestly, it’s the most effective method for thinning it out and removing air bubbles 🫧 We do a lot of skim coats and this is the trick.
Applying paint or texture over? It happens. The next coat will turn out just fine.